Green approach for fabrication of graphene from polyethylene terephthalate (PET) bottle waste as reactive material for dyes removal from aqueous solution: Batch and continuous study

This study is concerned with the synthesis of graphene from PET waste bottles as raw material and investigates the possibility of using it as an inexpensive and active material for the removal of methylene blue (MB) and methyl orange (MO) from aqueous solution. The synthesis process was achieved in a green way through the manufacture of a stainless steel autoclave that reduces the emission of toxic gases and accelerates the pyrolysis process. The synthesized graphene is characterized by FTIR, SEM, TEM, EDX, XRD, and surface area. Many factors that affect dyes removal percent were studied such as contact time, initial pH of the solution, agitation speed, initial concentration, and sorbent dosage. The sorption isotherm and kinetics study were described using two isotherm models (Langmuir and Freundlich) and two kinetic models (pseudo-first-order and pseudo-second-order), while the column experimental data were fitted with four breakthrough curve models (Thomas-BDST, Bohart–Adams, Yan, and Clark). The experimental results proved that the prepared graphene can be a promising reactive material for the removal of dyes (MB and MO) from aqueous solutions.